Riders wait for a train at the Metro Center station in Washington. / Karen Bleier, AFP/Getty Images

by Russ Ptacek, WUSA-TV

by Russ Ptacek, WUSA-TV

BETHESDA, Md. - WUSA9-TV found files documenting complaints of train and bus workers flipping off customers - including one incident with photos - and a discipline policy that allows employees to flip riders off and keep their jobs.

One employee of the Washington Metropolitan Area Transit Authority extended her middle finger long enough for a customer to take photos.

"I think the difficulty with photographs is they only show a snapshot in time," Metro spokeswoman Caroline Laurin said. "We don't know exactly what happened preceding the picture."

WMATA has denied a WUSA9 open-records request for all 2012 and 2013 complaints containing the terms "finger," "bird," "obscene," flipped" and "gesture," saying a response would be "unreasonably burdensome," would "generate approximately 722 records," "take 35 hours of staff time" and cost $2,556.

"It's our goal to make sure that our customers feel welcome and well treated," Laurin said. "Absolutely this isn't something we want to have happening."

Metro says its records document only four apologies for flipping customers off.

WMATA says discipline is handled on a case-by-case basis, determined by previous performance.